The most frequently asked questions are listed below. For an update refer to the Kipp & Zonen website at www.kippzonen.com
Q: What are typical values for downward atmospheric long wave radiation?
A:
Q: Is the pyrgeometer calibration affected by the length of the signal cable?
A: With longer cable lengths the impedance increases, however it does not affect the radiometer sensitivity for the following
reason. For the SGR-V the impedance of the voltage measurement device is at least 1000 times more than the impedance of the
pyrgeometer plus cable. Therefore the current that goes through the readout cable is negligible and won’t generate an offset.
For the SGR-A current versions the cable length is limited by the power supply voltage and voltage drop over the cable. However the
low cable impedance (150 Ω/km) and normally high impedance of the read-out unit / logger is normally no limitation.
The digital RS-485 output can operate over cable lengths up to 1000 m, depending on the baud-rate used.
9. Frequently asked questions
-20 °C
L
d↓
in W/m
2
0 °C
+30 °C
230
315
480
80
165
330
Overcast sky
(L
net
= 0 W/m
2
)
Ambient temperature
Clear sky
(L
net
= -150 W/m
2
)
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